com.dahuatech.hutool.json.InternalJSONUtil Maven / Gradle / Ivy

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package com.dahuatech.hutool.json;

import com.dahuatech.hutool.core.convert.Convert;
import com.dahuatech.hutool.core.date.DateUtil;
import com.dahuatech.hutool.core.util.CharUtil;
import com.dahuatech.hutool.core.util.NumberUtil;
import com.dahuatech.hutool.core.util.ObjectUtil;
import com.dahuatech.hutool.core.util.StrUtil;

import java.io.IOException;
import java.io.Writer;
import java.util.*;

/**
 * 内部JSON工具类，仅用于JSON内部使用
 *
 * @author Looly
 */
final class InternalJSONUtil {

  private InternalJSONUtil() {}

  /**
   * 写入值到Writer
   *
   * @param writer Writer
   * @param value 值
   * @param indentFactor 每一级别的缩进量
   * @param indent 缩进空格数
   * @param config 配置项
   * @return Writer
   * @throws JSONException JSON异常
   * @throws IOException IO异常
   */
  protected static Writer writeValue(
      Writer writer, Object value, int indentFactor, int indent, JSONConfig config)
      throws JSONException, IOException {
    if (value == null || value instanceof JSONNull) {
      writer.write(JSONNull.NULL.toString());
    } else if (value instanceof JSON) {
      ((JSON) value).write(writer, indentFactor, indent);
    } else if (value instanceof Map) {
      new JSONObject((Map) value).write(writer, indentFactor, indent);
    } else if (value instanceof Iterable
        || value instanceof Iterator
        || value.getClass().isArray()) {
      new JSONArray(value).write(writer, indentFactor, indent);
    } else if (value instanceof Number) {
      writer.write(NumberUtil.toStr((Number) value));
    } else if (value instanceof Date || value instanceof Calendar) {
      final String format = (null == config) ? null : config.getDateFormat();
      writer.write(formatDate(value, format));
    } else if (value instanceof Boolean) {
      writer.write(value.toString());
    } else if (value instanceof JSONString) {
      Object o;
      try {
        o = ((JSONString) value).toJSONString();
      } catch (Exception e) {
        throw new JSONException(e);
      }
      writer.write(o != null ? o.toString() : JSONUtil.quote(value.toString()));
    } else {
      JSONUtil.quote(value.toString(), writer);
    }
    return writer;
  }

  /**
   * 缩进，使用空格符
   *
   * @param writer writer
   * @param indent 随进空格数
   * @throws IOException IO异常
   */
  protected static void indent(Writer writer, int indent) throws IOException {
    for (int i = 0; i < indent; i += 1) {
      writer.write(CharUtil.SPACE);
    }
  }

  /**
   * 如果对象是Number 且是 NaN or infinite，将抛出异常
   *
   * @param obj 被检查的对象
   * @throws JSONException If o is a non-finite number.
   */
  protected static void testValidity(Object obj) throws JSONException {
    if (false == ObjectUtil.isValidIfNumber(obj)) {
      throw new JSONException("JSON does not allow non-finite numbers.");
    }
  }

  /**
   * 值转为String，用于JSON中。 If the object has an value.toJSONString() method, then that method will be
   * used to produce the JSON text. 

   * The method is required to produce a strictly conforming text. 

   * If the object does not contain a toJSONString method (which is the most common case), then a
   * text will be produced by other means. 

   * If the value is an array or Collection, then a JSONArray will be made from it and its
   * toJSONString method will be called. 

   * If the value is a MAP, then a JSONObject will be made from it and its toJSONString method will
   * be called. 

   * Otherwise, the value's toString method will be called, and the result will be quoted.

   *
   * @param value 需要转为字符串的对象
   * @return 字符串
   * @throws JSONException If the value is or contains an invalid number.
   */
  protected static String valueToString(Object value) throws JSONException {
    if (value == null || value instanceof JSONNull) {
      return "null";
    }
    if (value instanceof JSONString) {
      try {
        return ((JSONString) value).toJSONString();
      } catch (Exception e) {
        throw new JSONException(e);
      }
    } else if (value instanceof Number) {
      return NumberUtil.toStr((Number) value);
    } else if (value instanceof Boolean
        || value instanceof JSONObject
        || value instanceof JSONArray) {
      return value.toString();
    } else if (value instanceof Map) {
      Map map = (Map) value;
      return new JSONObject(map).toString();
    } else if (value instanceof Collection) {
      Collection coll = (Collection) value;
      return new JSONArray(coll).toString();
    } else if (value.getClass().isArray()) {
      return new JSONArray(value).toString();
    } else {
      return JSONUtil.quote(value.toString());
    }
  }

  /**
   * 尝试转换字符串为number, boolean, or null，无法转换返回String
   *
   * @param string A String.
   * @return A simple JSON value.
   */
  protected static Object stringToValue(String string) {
    Double d;
    if (null == string || "null".equalsIgnoreCase(string)) {
      return JSONNull.NULL;
    }

    if (StrUtil.EMPTY.equals(string)) {
      return string;
    }
    if ("true".equalsIgnoreCase(string)) {
      return Boolean.TRUE;
    }
    if ("false".equalsIgnoreCase(string)) {
      return Boolean.FALSE;
    }

    /* If it might be a number, try converting it. If a number cannot be produced, then the value will just be a string. */
    char b = string.charAt(0);
    if ((b >= '0' && b <= '9') || b == '-') {
      try {
        if (string.indexOf('.') > -1 || string.indexOf('e') > -1 || string.indexOf('E') > -1) {
          d = Double.valueOf(string);
          if (!d.isInfinite() && !d.isNaN()) {
            return d;
          }
        } else {
          Long myLong = new Long(string);
          if (string.equals(myLong.toString())) {
            if (myLong == myLong.intValue()) {
              return myLong.intValue();
            } else {
              return myLong;
            }
          }
        }
      } catch (Exception ignore) {
      }
    }
    return string;
  }

  /**
   * 将Property的键转化为JSON形式

   * 用于识别类似于：com.luxiaolei.package.hutool这类用点隔开的键
   *
   * @param jsonObject JSONObject
   * @param key 键
   * @param value 值
   * @return JSONObject
   */
  protected static JSONObject propertyPut(JSONObject jsonObject, Object key, Object value) {
    String keyStr = Convert.toStr(key);
    String[] path = StrUtil.split(keyStr, StrUtil.DOT);
    int last = path.length - 1;
    JSONObject target = jsonObject;
    for (int i = 0; i < last; i += 1) {
      String segment = path[i];
      JSONObject nextTarget = target.getJSONObject(segment);
      if (nextTarget == null) {
        nextTarget = new JSONObject();
        target.put(segment, nextTarget);
      }
      target = nextTarget;
    }
    target.put(path[last], value);
    return jsonObject;
  }

  /**
   * 默认情况下是否忽略null值的策略选择

   * JavaBean默认忽略null值，其它对象不忽略
   *
   * @param obj 需要检查的对象
   * @return 是否忽略null值
   * @since 4.3.1
   */
  protected static boolean defaultIgnoreNullValue(Object obj) {
    return (false == (obj instanceof CharSequence)) //
        && (false == (obj instanceof JSONTokener)) //
        && (false == (obj instanceof Map));
  }

  /**
   * 按照给定格式格式化日期，格式为空时返回时间戳字符串
   *
   * @param dateObj Date或者Calendar对象
   * @param format 格式
   * @return 日期字符串
   */
  private static String formatDate(Object dateObj, String format) {
    if (StrUtil.isNotBlank(format)) {
      final Date date = (dateObj instanceof Date) ? (Date) dateObj : ((Calendar) dateObj).getTime();
      // 用户定义了日期格式
      return JSONUtil.quote(DateUtil.format(date, format));
    }

    // 默认使用时间戳
    return String.valueOf(
        (dateObj instanceof Date)
            ? ((Date) dateObj).getTime()
            : ((Calendar) dateObj).getTimeInMillis());
  }
}